Carpet weaving

ABSTRACT

A carpet weaving loom including at least one tuft forming unit ( 1 ) for forming sequentially yarn tufts ( 7 ) of a number of different colors, means to receive and hold at yarn tuft holding sites ( 8 ) yam tufts supplied sequentially by the tuft forming unit ( 1 ), and transfer means ( 10 ) to transfer all of the tufts ( 7 ) held by the yarn tuft holding sites ( 8 ) simultaneously to their corresponding weaving points. The or each tuft forming unit supplies yarn tufts ( 7 ) to at least twenty yarn tuft holding sites ( 8 ) between successive operations of the transfer means ( 10 ). When only a single tuft forming unit ( 1 ) is provided it preferably supplies tufts to at least one hundred and sixty tuft holding sites ( 8 ). When a plurality of tuft forming units ( 1 ) are provided each preferably supplies tufts to between twenty and one hundred and twenty tuft holding sites ( 8 ). This configuration leads to a considerable reduction in the size of creel with consequent reduction in waste and time taken to thread-up such a loom.

BACKGROUND TO THE INVENTION

In making carpet, particularly patterned Axminster carpet, a yarn tuftforming unit is used to provide yarn of a particular colour to eachweaving point of the carpet. In conventional Axminster weaving there aretwo principal ways which the yarn tuft formation is carried out. Thefirst way is on a Jacquard Axminster loom, and the second is on a spoolAxminster loom.

On a gripper Jacquard Axminster loom each weaving point includes a yarncarrier which is normally fed by eight yarns usually of different colourand the Jacquard mechanism moves the carrier to bring a selected yarn tothe yarn selection position. A gripper moves towards the carrier, gripsthe yarn at the yarn selection position then relative movement apart ofthe gripper and the carrier pulls a predetermined length of yarn fromthe carrier. The yarn is then cut to form a tuft and moved by thegripper to the weaving point. The tuft carried by the gripper is of theappropriate colour for the tuft to be supplied to the next row of carpetto be woven. For a conventional 12 foot (4 m) loom there are over a 1000weaving points across the loom and thus the creel supplying yarn to theloom has to have the potential of carrying over 8000 yarn packages.Typically, when the creel includes measured quantities of yarn in eachyarn package, an allowance of an additional eighteen metres of yarn isprovided in each yarn package. Accordingly, the greater the number ofyarn packages the greater the wastage. In spite of such a large creelsize a designer of such carpets is relatively limited since the numberof colours available for each column of tufts extending in the warpdirection of the finished carpet and corresponding to a single weavingpoint is limited to only eight throughout each pattern repeat. Jacquardsare also known in which the yarn carrier can hold sixteen differentyarns. These require an even larger creel.

Spool Axminster looms provide a designer with greater flexibility. Inspool Axminster looms a separate spool is provided for each row of thepattern repeat and each spool has a separate yarn winding for eachweaving point along each row. Therefore, at least theoretically, thedesigner has an infinite number of colour choices for each column androw of each pattern repeat. However, in practice, as the number ofcolour choices used for each column and row of the design increases, thenumber of yarn packages needed for the spool winding operation alsoincreases. Further, the spool winder must be set up differently for thewinding of each spool which is time consuming. When a large number ofdifferent colours are used in both the column and row or warp and weftdirection of each pattern repeat the number of different coloured yarnpackages supplying the spool winder can be even larger than those on acreel of a typical Jacquard Axminster loom. The pattern repeat on spoollooms is limited by the number of spools available in the spool chain.Further, there is considerably greater yarn wastage from a spoolAxminster loom than a gripper Axminster loom because, on completion of arun, waste is generated from each weaving point of each row of thepattern repeat.

DISCUSSION OF PRIOR ART

In both the Jacquard and spool Axminster looms a row of tufts for acomplete row of the carpet is created simultaneously and transferred tothe weaving point at which they are woven into a backing to produce thecarpet. An entirely different approach to yarn selection for carpetproduction has recently been proposed in WO 95/31594. In this, it isproposed that tufts of yarn to form a row of the carpet are produced byfirst loading yarn tufts into a tuft carrier and then transferring theyarn tufts from the tuft carrier to the weaving points. To achieve thisa large number of different tuft forming units, typically one perweaving point, are provided along the length of a path with typicallyeach tuft forming unit being supplied with yarn of only a single colour.As the tuft carrier is moved along the path it receives tufts ofappropriate colour in each of its tuft holding sites. The tuft carrieris subsequently moved so that all the tufts for each row can be grippedby grippers and transferred to the weaving point simultaneously. Thus,the tufts are not usually all formed simultaneously and hence the tuftformation is, at least to some extent, decoupled from the weavingoperation. Therefore, tuft formation can take place at the same time asthe weaving operation and thus tuft formation can take placesubstantially continuously throughout the operation of the loom. This isto be contrasted with conventional spool or gripper type looms wheretuft formation takes place over only about half of each weaving cycle.

In examples given in WO 95/31594 it is suggested that partly as a resultof forming the tufts throughout the entire weaving cycle it is possibleto, for example, increase the speed of the tuft forming operation byfour times. It is also explained that if this were possible and it wasintended to operate the loom at the same speed as a conventional loomthen it would be possible to reduce the size of its creel to a quartersince, in effect, each tuft forming unit would supply tufts for fourweaving points. However, nowhere in this document does it exemplify anarrangement in which there are less yarn packages than the number ofweaving points.

Whilst the above document specifically exemplifies only the supply ofyarn of a single colour to each tuft forming unit it does disclose thetheoretical possibility of providing yarn of a number of differentcolours to each tuft forming unit and somehow, in an unspecified way,selecting yarn of an appropriate colour for each weaving point. If thisteaching is followed the creel size would not be reduced significantly.The document also discusses the theoretical possibility of holding theyarn carrier stationary whilst moving the tuft forming unit. However,neither of these theoretical possibilities are exemplified nor is itexplained how they could be achieved nor what advantages would accrue.

SUMMARY OF THE INVENTION

According to this invention a carpet weaving loom includes at least onetuft forming unit for forming sequentially yarn tufts of a number ofdifferent colours, means to receive and hold at yarn tuft holding sitesyarn tufts supplied sequentially by the tuft forming unit, and transfermeans to transfer all of the tufts held by the yarn tuft holding sitessimultaneously to their corresponding weaving points, the or each tuftforming unit supplying yarn tufts to at least twenty yarn tuft holdingsites between successive operations of the transfer means.

The number of tuft forming units provided on the loom varies with thewidth of the loom and its required operating speed. For example, on aloom used to make carpet samples there will usually only be a singletuft forming unit and this tuft forming unit may supply tufts to, forexample, three hundred, or more, tuft holding sites. On a typical twelvefoot (4 m) loom there may be twelve tuft forming units each supplyingtufts to less than one hundred and twenty holding sites and typicallyaround eighty tuft holding sites. However, to be able to operate such aloom at the highest possible speed the number of tuft forming units maybe increased to twenty four or even thirty with each supplying just overforty or about thirty five tuft holding sites. In the case of therebeing more than one tuft forming unit these are preferably subsequentlyequidistantly spaced across the loom.

Taking the typical case given above of a twelve toot (4 m) loomincluding twelve tuft forming units and assuming an equal choice ofdifferent yarns, eight, as used in a typical conventional gripperAxminster loom, the creel of such a loom only requires ninety sixdifferent yarn packages. This is nearly a hundred-fold decrease in thenumber of yarn packages from that required in the conventional loom.Taking the case of thirty tuft forming units this still leads to atleast a thirty-fold decrease in the number of yarn packages. Reducingthe size of the creel by such amounts leads to an equivalent reductionin the set-up time required to thread up the loom as well as potentiallyhaving significantly less waste as a result of a much smaller number ofyarn packages on the creel.

Preferably the or each tuft forming unit is capable of forming tuftsfrom at least eight different yarns and preferably at least ten. Thenumber of different yarns fed to the or each tuft forming unit may be ashigh as twenty four or even thirty two. Increasing the number ofdifferent yarns fed to the or each tuft forming unit increases thenumber of yarn packages in the creel but gives a carpet designer agreater number of colour choices in each column of tufts extending inthe warp direction over a conventional loom. In spite of any increasedue to the greater colour choice there is always a significant reductionin the overall number of yarn packages in the creel.

Preferably the or each tuft forming unit comprises a yarn selector wheelwith provision for holding a number of different yarns arranged aroundit, means to drive the selector wheel into a selected one of a number ofangularly discrete positions to bring a selected yarn to a loadingposition, a puller for engaging the selected yarn at the loadingposition and for pulling a predetermined length of the selected yarnfrom the selector wheel, and a cutting mechanism to cut the selectedyarn to form a tuft of predetermined length.

The yarns may be arranged around the periphery of the selector wheelgenerally parallel to its axis of rotation but preferably the yarnsextend generally radially to the periphery of the selector wheel.Typically, such a yarn selector wheel has provision for containing morethan 10 different yarns and typically 12, 16, 24 or 32 different yarns.Preferably the selector wheel is driven into and between itspredetermined angular positions by a servomotor under the control of acomputer.

Preferably the motion required to operate the cutter, provide openingand closing movements of the jaws of the puller, and to move the pullerforwards and backwards to pull yarn from the selector wheel and in turnfrom the creel are all driven from a so-called “gearbox” forming part ofthe tuft forming unit. The gearbox may be driven by a servomotor underthe control of a computer and in this way it can be ensured that thetiming of the puller and cutter movements can be synchronised with therotation of the selector wheel.

Alternatively a separate computer controlled servomotor may be providedto drive each motion of the cutter and puller and, in this case, thecomputer ensures the appropriate timing of the motions in synchronismwith the rotation of the selector wheel.

Preferably the or each tuft forming unit also includes a yarn detectorto ensure that yarn is present between the puller and the selector wheelafter the puller has moved away from the selector wheel. Typically thisyarn detector is formed by a simple light emitter and detectorarrangement on opposite sides of the path of the yarn. In this way whenthe optical detector detects the presence of light emitted by theemitter this indicates that no yarn is present. Typically, such anindication is used to stop the operation of the loom until any problemhas been rectified to ensure that each and every tuft required is formedcorrectly.

The carpet weaving loom may be formed in a way which is generallysimilar to that described in WO 95/31594 in which the or each tuftforming unit remains generally stationary and the means to receive andhold the yarn tufts at yarn tuft holding sites is formed by a tuftcarrier which moves past the or each tuft forming unit. After beingcompletely filled the tuft carrier is then transferred to a position toenable the tufts for a whole row to be taken from it simultaneously tobe woven into a carpet. Alternatively, the or each tuft forming unit isarranged to traverse all or part of the width of the loom and providetufts for the weaving points passed as the tuft forming unit or unitsmove transversely across the loom.

As an example of the latter of these, the means to receive and hold yarntufts may be formed by yarn tuft carriers which extend transverselyacross the loom. The, or each tuft forming unit moves along one of theyarn tuft carriers filling each of its tuft retention sites in turn withsequentially cut tufts, and, once all of the sites have been filled thatyarn tuft carrier is moved towards the transfer means and an empty yarntuft carrier is moved into a position adjacent the or each tuft formingunit. The yarn tuft carriers may be mounted equiangularly spaced aroundan axis and rotated as each yarn tuft carrier is filled. Alternatively,they may be mounted parallel to one another on an endless belt whichmoves the yarn tuft carriers from adjacent the or each tuft forming unitto the transfer means. In this case the transfer means correspond to thegripper arrangement of a conventional Axminster gripper loom and gripthe cut tufts held in the yarn tuft carrier and move them to the weavingpoint at which they are woven into the carpet and released.

In another example the means to receive and hold yarn tufts may includea pocket which is associated with each weaving point and which receivesthe yarn tuft after it is formed by the or each tuft forming unit. Eachtuft may be directed towards its associated pocket by an air flowcreated by applying a vacuum to the particular pocket next to receive acut tuft. Preferably the vacuum is applied to the pockets in turn as theor each tuft forming unit moves along the row of pockets. One way ofachieving this commutation between the supply of vacuum and the pocketsis to provide an elongate vacuum chamber with an apertured sliding frontplate; the plate being arranged to move with the tuft forming unit orunits transversely across the loom so that the aperture or apertures inthe plate are aligned with air exhaust ports of a particular pocket orparticular pockets as the tufts for that pocket or those pockets arecut. The air flow entrains each cut tuft and guides it into itsrespective pocket.

Preferably the pockets are bounded at their bases by retractable pinsand whilst the tufts are being formed the pins are in their forwardsposition defining a floor for each of the pockets. The pockets that holdeach tuft are preferably formed at the upper end of a channel and whenall of the pockets have been loaded with cut tufts, the pin floor isretracted and then punchers, one for each pocket, are rotated to engageeach tuft and push it along its respective channel to engage it with anose board of the loom. As the punchers withdraw, the tufts are thenwoven into the backing and once the punchers have withdrawn, tufts toform the next row are fed into the pockets. In this example the channelsand punchers thus form the tuft transfer means.

A rapier drive for weft insertion, the shedding of the warp threads anda lay beam with beat up reeds for a beat up operation on the woven intufts are provided in both of the above examples and, in general, theyare entirely conventional in arrangement and operation.

By providing sufficient tuft forming units the loom can operate as fastas a conventional gripper Axminster loom and so weave at a rate of aboutforty rows of tufts per minute. With the time saved in threading up theloom and creel there is a great reduction in “downtime” which leads to aconsiderable increase in carpet production from each loom which alsotypically provides an increase in the choice of colours throughout thewoven carpet with less waste of yarn. It is also possible to have fewertuft forming units and have the loom operating at a slower weaving speedthan a conventional loom and still achieve a similar carpet output as aresult of the shorter “downtime” offsetting the slower weaving speed.

One of the most significant contributions to the speeding up of the tuftforming operation and hence to the practicality of the present inventionis the arrangement of the so-called “gearbox” that provides the pullerand cutter motions in the or each tuft forming unit. Preferably thegearbox comprises a housing carrying three parallel shafts on which aremounted three equal size pinions meshed together. One of the shafts isdriven, typically by a servomotor, and all three pinions or shafts carryeccentric pins. One end of the puller is pivoted to the housing and itsother end is bifurcated to provide a pair of jaws. One of the eccentricpins is connected to a rod mounted for sliding movement along the pullerbody and carrying an orthogonal jaw operating pin. The eccentric pincauses the puller to pivot backwards and forwards and the orthogonal jawoperating pin to move up and down. The up and down movement of the jawoperating pin between facing cam surfaces of the bifurcated jaws causesthe jaws to open and close. Thus the puller moves forward, the jawsclose, the puller moves backwards, the jaws open and the cycle isrepeated for each rotation of the shaft. Another of the eccentric pinsdrives a knife blade via a link to cut the yarn to form a tuft.

Another important preferred feature of the tuft forming unit is tohandle the tuft positively at all times so that it is always undercontrol. One way of achieving this is to include a pair of cheeks spacedapart and mounted perpendicularly to the knife blade. As the knife bladeis lowered to cut the yarn to form a tuft, the yarn to form the tuft istrapped between the cheeks so that, even when released from the pullerand cut, it is still held positively between the cheeks. In this casethe tuft forming unit preferably includes a pusher which passes betweenthe cheeks to push the tuft out from between them. The pusher is drivenvia a link and a centrally pivoted first order lever from the remainingeccentric pin. The cheeks may be arranged to move up and down and alsobe driven from the remaining eccentric pin, or by being mounted on theknife blade. The eccentric pins are timed with respect to one another sothat then yarn is held between the cheeks; the tuft is released from thejaws of the puller; the pusher initially engages the yarn whilst it isheld between the cheeks; then the yarn is cut to form the tuft; and thenthe pusher finally pushes the cut tuft out from between the cheeks.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular examples of a loom in accordance with this invention will nowbe described with reference to the accompanying drawings, in which:

FIG. 1 is a sectional side elevation of a first example of loom duringthe tuft forming process and showing the puller in a first position;

FIG. 2 is a sectional side elevation of the first example of loom duringthe tuft transfer operation and showing the puller in a second position;

FIG. 3 is a partial front elevation of the first example of loom;

FIG. 4 is an underplan of the selector wheel to a larger scale;

FIG. 5 is a sectional side elevation of a first example of tuft formingunit drawn to a larger scale and from the opposite direction;

FIG. 6 is a front elevation of the first example of tuft forming unitdrawn to a larger scale showing the cutter;

FIG. 7 is a front elevation similar to FIG. 6 but with part of thecutter cut away to show the puller in more detail.

FIG. 8 is a sectional side elevation of a second example of loom duringthe tuft forming process;

FIG. 9 is a simplified sectional side elevation of a second example oftuft forming unit, drawn to a larger scale and from the oppositedirection, at the start of the tuft forming operation;

FIG. 10 is a simplified sectional side elevation of a second example oftuft forming unit, drawn to a larger scale and from the oppositedirection, at the end of the tuft forming operation; and,

FIG. 11 is a simplified front elevation showing two of the secondexamples of tuft forming units.

DESCRIPTION OF PARTICULAR EMBODIMENTS

Both examples of Axminster loom are capable of weaving 12 foot (4 metre)wide Axminster carpet at a pitch of seven tufts per inch (25.4 mm). Tuftyarn is supplied from a creel (not shown) to twelve tuft forming units1, equidistantly spaced across the loom. The tuft forming units 1 aremounted on a common framework. The framework and tuft forming units aremoveable transversely backwards and forwards across the loom by arecirculating ball nut assembly 5 driven from a servomotor 6 (shown inFIGS. 3 and 11).

In the first example the framework includes plate 2, shaft 3 and hangers4, and can also be pivoted about the shaft 3 by a pneumatic ram (notshown) so that the yarn transfer units 1 move between the positionsshown in FIGS. 1 and 2. The tuft forming units 1, which will bedescribed in more detail subsequently, form tufts 7 which fall intopockets 8 formed in the top of a fin pack assembly 9. The fin packassembly 9 consists of a number of parallel plates separated by shapedspacers to provide clearance between adjacent plates for passage ofpunchers 10 and beat up reeds 11. The spacers also define an air channel12 between each pocket 8 and a vacuum chamber 13. The air channelsterminate in a series of rounded apertures 14 located at the side ofeach of the pockets 8. The fin pack 9 also includes an aperture 15 forthe needle or rapier 16 and weft threads.

After the tuft forming units 1 have loaded tufts 7 into each of thepockets 8, the tuft forming units 1 are pivoted into the position shownin FIG. 2 and then the punchers 10 rotate in the clockwise direction, asshown in FIG. 1, to transfer the cut tufts 7 from the pockets 8 to aposition against a nose board 17 where they are woven into the backingof a carpet by weft threads inserted by the rapier 16. The punchers 10return to their initial position to allow the tuft forming units 1 topivot backwards and start loading the pockets 8 with further tufts 7 toform the next row whilst the reeds 11 perform a beat up operation on therow of tufts that have just been woven in to produce the finished carpet18. Stuffer and chain warp yarns 19 pass through a conventional sheddingarrangement 20 to shed the warp yarns 19 between each lash of the rapier16.

Each tuft forming unit 1 includes a rotatable selector wheel 20, shownmost clearly in FIG. 4, which is mounted on a shaft driven by aservomotor 21. The selector wheel 20 includes twenty-four generallyradially extending channels 22 each of which carries a tuft forming yarn23 of a different colour. The tuft forming yarns 23 are fed from thecreel to the tuft forming units using entirely conventional yarn tubesand guides and then pass through multi-aperture guides 24, 25 and 26before passing through a series of apertures 27 formed in a portion ofthe selector wheel 20. The yarns are held in place in the channels 22 byspring fingers (not shown).

Each tuft forming unit 1 also includes a cutter 28 and puller 29 whichare shown most clearly in FIGS. 5, 6 and 7. The cutter 28 comprises afixed blade 30 with an aperture 31 and a moving blade 32. The aperture31 is adjacent the edge of the selector wheel 20 and the free ends ofthe yarns 23 extending radially outwards from the selector wheel 20extend into the aperture 31. The moveable blade 32 is pivoted around apivot 33 and driven by a pivoted link 34, pivotally connected to a crank35 forming part of the moving blade 32 and a crank 36 mounted on shaft37. The puller 29 comprises a generally U-shaped portion 38 withelongate parallel limbs 39 and 40 and gripping jaws 41 and 42 secured totheir free ends. This is shown most clearly in FIGS. 5 and 7. Thegripping jaws 41 and 42 are normally held closed by the resilience ofthe U-shaped portion 38. However, by moving a pin 43 downwards as shownin FIG. 7 between a pair of raised cam-surfaces 44 and 45, the limbs 39and 40 move apart and so open the jaws 41 and 42. The puller 29 is alsomounted for rotation about shaft 46, shown in FIG. 5, between theposition shown in FIG. 5 and a forwards position shown in FIG. 1 withthe gripping jaws 41 and 42 extending into the aperture 31 in the fixedcutting knife blade 30 and adjacent the selector wheel 20.

The rotation of the shaft 37, the up and down movement of the pin 43 andthe oscillation of the shaft 46 are all driven through a gear box 47which will be described in more detail subsequently. The gear boxes 47are all driven from a toothed pulley 48 mounted on a shaft, not shown.The pulleys 48 of all of the tuft forming units 1 are driven via toothedbelts 50 from pulleys 51 mounted on a shaft 52 driven by a servomotor53, shown in FIG. 3. The shaft 52 and servomotor 53 are mounted on theframe 2, 3 and 4 and so move transversely with the tuft forming units 1.

A light emitting diode and photo detector (not shown) are coupled toends of optical fibres which are located in apertures 54 located betweenthe jaws 41 and 42 and the knife 28. When the puller 29 has gripped thefree end of one of the yarns 23 and pulled it out, and before the knife28 operates, the yarn 23 is positioned in between the optical fibrecoupled to the photo detector and that coupled to the photo emitter andso blocks light from the emitter reaching the detector. Provided lightfrom the photo emitter is prevented from reaching the photo detector atthis time it is assumed that a yarn has been successfully pulled out ofthe selector wheel 20 by the puller 29. However, if at this time in theoperating cycle of the tuft forming unit light from the photo emitter isdetected by the photo receiver then it is assumed that the tuft has notbeen correctly formed and a stop signal is given to the loom to preventits further operation until the situation has been rectified.

During each tuft forming cycle the servomotor 21 drives the selectorwheel 20 into a predetermined angular position so that either a blankspace 55 at a central position is adjacent the puller 29 or one of theyarns 23 is adjacent the puller 29. During each tuft forming cycle thepuller rotates in the anti-clockwise direction as shown in FIG. 5 aroundthe axis of shaft 46 so that the jaws 41, 42 move forward and closetogether, then, the puller rotates clockwise about the axis of shaft 46so that the jaws move backwards and then the jaws 41 and 42 open. Thus,during each tuft forming cycle either a central blank position 55 isadjacent the puller when no carpet is to be woven, or yarn of a selectedcolour is presented to the puller 29 upon indexing of the selector wheel20 to the required angular position. Thereupon the puller 29 grabs theyarn end presented to it, pulls a predetermined length of yarn,typically half of an inch (12.5 mm), from the yarn supply on the creeland then the yarn is severed by the knife 28 to produce a yarn tuft 7.The selector wheel 20 is then free to rotate to a different angularposition to provide the next tuft to be formed. The puller 28 thenreleases the yarn before moving forward again to form the next yarn tuft7.

The operation of the servomotor 21, the servomotor 6 and the servomotor53 are all controlled by a computer driven controller to ensure thatappropriate coloured yarns are provided to each weaving point to providethe required pattern in the resulting carpet 18. The computerisedcontroller has inputs corresponding to the transverse position of thetuft forming units 1 across the width of the loom and for any particularrow of a pattern which is to be woven at any instant, to enable it tocontrol the tuft forming units 1 effectively.

After the tuft 7 is formed, cut by the knife 28 and released by the jaws41, 42 of the puller 29 it is pulled down into the required position inthe pocket 8 by an air flow generated by the vacuum chamber 13. Thefront of the vacuum chamber 13 is closed by a sliding shutter plate 57containing twelve slots, the number corresponding to a number of tuftforming units 1. The sliding shutter plate 57 is connected to theframework 2, 3 and 4 and so moves with the tuft forming units 1. Each ofthe apertures in the sliding shutter plate 57 is generally aligned withits respective tuft forming unit 1 so that when the tuft forming unit 1is in place above a particular pocket 8 the aperture in the shutter isaligned with the rear edge of the arcuate channel 12 to apply a vacuumto the rear of channel 12 and hence to the apertures 14 so that air isdrawn into the pocket 8, through the apertures 14, through the arcuatechannel 12 and into the vacuum chamber 13. It is this airflow whichentrains the tuft 7 after it is cut by the cutter 28 and released by thepuller 29 to pull the tuft down into the pocket 8. The bottom of eachpocket 8 is defined by a retractable pin (not shown). As the tuftforming units 1 move along so the sliding shutter commutates the vacuumfrom the chamber 13 to the next pocket 8, and so on across the width ofthe loom.

Once all of the pockets 8 have been loaded with tufts 7 the tuft formingunits 1 are pivoted into their position shown in FIG. 2 and the pinsforming the floor of each of the pockets are retracted. The punchers 10then rotate in a clockwise direction and so move forwards and downwards.An angled face 58 on each of the punchers 10 engages its correspondingtuft 7 to push it downwards between adjacent fins of the fin package 10.By providing a predetermined angle on the contact face 58 of the puncher10 and, in particular a notch 59 at the end of the contact face 58,whilst the puncher 10 is forcing the tuft 7 between adjacent fins of thefin package the tuft 7 moves along the angled face 58 of the puncher 10until its end is stopped by the notch 59. This precisely locates thetuft 7 in a predetermined position so that when it reaches the weavingpoint defined by the nose board 17 it is in the correct location. At theweaving point the punchers 10 push the cut tuft 7 against the nose board17 and then the tuft is woven into position by the application of weftthreads using the rapier 16 as the puncher 10 returns anti-clockwise toits starting position. To complete the formation of the carpet 17 alay-beam with attached reeds 11 beats up the tuft and weft yarns tocomplete the formation of that row of carpet whilst the tufts 7 for thenext row are being placed in the pockets 8.

The second example of loom shown in FIG. 8 is generally similar to thefirst, especially in operation, but instead of the finpack and punchersfor transferring the cut tufts to the weaving point, it includes a pairof tuft carriers 70 mounted for rotation about an axis 71 and a set ofconventional grippers 72 that are entirely conventional in constructionand use. As the tuft forming units 1 traverse the loom, tufts are placedin tuft retention sites 73 formed along the top edge of the tuft carrier70. When all of the tuft retention sites have been loaded, the tuftcarrier 70 rotates clockwise (as seen in FIG. 8) about the axis 71 tomove the loaded tuft carrier 70 into the lowermost position and to movean empty tuft carrier 70 into the uppermost position. The tuft formingunits 1 then load tufts 7 into the uppermost tuft carrier 70 as theytraverse backwards across the loom. The grippers 72 move upwards,clockwise as seen in FIG. 8, with their beaks open and then close togrip all of the tufts 7 held by the lowermost tuft carrier 70. Thegrippers 72 then rotate in the opposite direction to move the tufts 7 tothe weaving point where the tufts 7 are woven into the carpet and thegrippers 72 open to release the tufts 7. The beat up reeds 11 and rapierweft insertion mechanism have been omitted from FIG. 8 for clarity butare entirely conventional and similar to those used on conventionalgripper Axminster carpet looms.

Another difference between the first and second examples is the mountingof the tuft forming units 1. In the second example the tuft formingunits 1 are mounted on a framework 80 including grooved rollers 81 whichrun on beveled rails 82. This permits the tuft forming units 1 and theframework 80 to move transversely across the loom and once again it isdriven by a recirculating ball-nut/screw mechanism 83 driven byservomotor 5.

The second example of tuft forming unit 1 shown in simplified form forease of explanation in FIGS. 8 to 11 provides positive handling of eachyarn tuft 7 during its formation and upon insertion into each tuftholding site on yarn carrier 70 or into each pocket 8 so avoiding theneed for the vacuum chamber 13 and airflow arrangements describedpreviously. Each yarn tuft forming unit 1 includes a gear box shown in asimplified fashion in FIGS. 9 to 11. It consists of three parallelshafts 90, 91, 92 on which are mounted three equal sized pinions 93, 94,95 which are meshed together. One of the shafts 90, 91, 92 is drivendirectly by the servomotor 53 or via the toothed belt and pulleyarrangement already described or by a further pinion 96 as shown in FIG.11. All three shafts 90, 91, 92 are drilled to carry eccentric pins. Pin97 is mounted in shaft 90 and is connected to rod 98 and pin 99. Rod 98is journalled into body 100 of the puller 29 so that it can slide up anddown as seen in FIGS. 9 and 10. The body 100 is pivoted at its upper endon pivot 101. Consequently, as shaft 90 rotates, counterclockwise asseen in FIG. 9, the pin 97 and rod 98 move up and down with respect tothe body 100 and the body 100 is caused to pivot backwards and forwardsabout its pivot 101. In this example the puller includes a pair ofpivoted limbs 102, 103 with jaws 104, 105 mounted at their lowermostends. The upper ends of the limbs are urged together by a spring 106 tocause the limbs to pivot and open the jaws 104, 105. The pin 99 moves upand down with respect to cam surfaces 107, 108 on the limbs 102, 103 tourge the jaws 104, 105 together when in its uppermost position and, inits lowermost position, allow the limbs 102, 103 to respond to the biasexerted by the spring 106, to open the jaws 104, 105.

The moveable blade 32 of the knife assembly is driven up and down by alink 109 connected between the moveable blade 32 and an eccentric pin110 mounted in the shaft 91. The rear face of the moveable knife bladecarries a pair of guide cheeks 112 which locate between the limbs 102,103 when they are in their forwards position. An eccentric pin 113 inthe third shaft 92 drives one end of a first order lever 114 via a link115. A pusher 116 located at the other end of the first order lever 114moves up and down between the guide cheeks 112.

To produce each tuft, the yarn selector motor 21 rotates the selectorwheel 20 to bring the selected yarn to a location adjacent the puller29. The body 100 of the puller is pivoted forwards with the pin 99towards its lowermost position so that the jaws 104, 105 are open. Asthe shaft 90 continues to rotate the pin 99 lifts and is moved betweenthe cam surfaces 107, 108 so closing the jaws 104, 105 and clamping thefree end of the yarn between them. Further rotation of the shaft 90causes the body 100 of the puller 29 to pivot backwards so pulling yarnfrom the selector wheel 20. Rotation of shaft 91 causes the moveableblade 32 of the knife assembly 29 to move downwards. As the blade movesdownwards the length of yarn being pulled by the puller 29 is trappedbetween the guide cheeks 112. Once the puller 29 has moved backwards toits maximum extent the continued downwards movement of the knife blade32 cuts the yarn to form a tuft 7 which is held between the guide cheeks112 as the knife blade 32 continues to move downwards on an overtravel.Meanwhile rotation of shaft 92 causes the pusher 116 to move downwardsbetween the guide cheeks 112. Further rotation of shaft 90 causes thepin 99 to be lowered away from the cam surfaces 106, 107 so that thejaws 104, 105 open under the action of the spring 106. Further rotationof the shaft 92 brings the pusher into contact with the top of the tuft7 held between the guide cheeks 112 and continued rotation of the shaft92 causes the tuft 7 to be pushed into a tuft retention site 73 on thetuft carrier 71 or into the pocket 8 in the first example. Continuedrotation of the shaft 91 moves the moveable knife blade 32 upwards.Meanwhile the yarn selector motor 21 moves the selector wheel 20 tobring the next yarn to be selected into position. Continued rotation ofshafts 90 and 92 move the puller 29 forwards into position to grip thenext yarn and move the pusher 116 upwards ready for the next cycle ofoperation.

With this second arrangement of tuft forming unit, since the tuft ispositively held at all times, whether by the jaws 104, 105, the guidecheeks 112, or the pusher 116 the tuft is always at a known and fixedposition. This leads to improvements in tuft placement in the carpet andhence to less waste of tuft yarn as a result of less material beingremoved during a subsequent shearing step. Positive handling of the cuttuft, particularly by the pusher 116 also enables the jaws 104, 105 tohave matching serrated teeth so that they grip the yarn more positivelywhilst drawing the yarn through the selector wheel 20 and from thecreel. Preferably the serrated teeth are similar to those used on thegrippers of a conventional Axminster loom.

What is claimed is:
 1. A carpet weaving loom including at least one tuftforming unit (1) for forming sequentially yarn tufts (7) of a number ofdifferent colours, means to receive and hold at yarn tuft holding sites(8,73) yarn tufts (7) supplied sequentially by the tuft forming unit(1), and transfer means (10,72) to transfer all of the tufts (7) held bythe yarn tuft holding sites (8,73) simultaneously to their correspondingweaving points, characterized in that the or each tuft forming unit (1)supplies yarn tufts to at least twenty yarn tuft holding sites (8,73)between successive operations of the transfer means (10,72).
 2. A carpetweaving loom according to claim 1, in which there is only a single tuftforming unit (1) and the single tuft forming unit (1) supplies tufts toat least one hundred and sixty tuft holding sites (8,73).
 3. A carpetweaving loom according to claim 1, in which a plurality of tuft formingunits (1) are provided.
 4. A carpet weaving loom according to claim 3,in which the tuft forming units (1) are substantially equidistantlyspaced in the transverse direction across the loom.
 5. A carpet weavingloom according to claim 3, in which each tuft forming unit (1) suppliestufts to between twenty and one hundred and twenty tuft holding sites.6. A carpet weaving loom according to claim 1, in which the or each tuftforming unit (1) is capable of forming tufts from at least eightdifferent yarns and preferably at least ten.
 7. A carpet weaving loomaccording to claim 1, in which the or each tuft forming unit (1) iscapable of forming tufts from at least twenty four different yams.
 8. Acarpet weaving loom according to claim 1, in which the or each tuftforming unit (1) comprises a yarn selector wheel (20) with provision forholding a number of different yarns arranged around it, means (21) todrive the selector wheel (20) into a selected one of a number ofangularly discrete positions to bring a selected yarn to a loadingposition, a puller (29) for engaging the selected yarn at the loadingposition and for pulling a predetermined length of the selected yarnfrom the sector wheel (20), and a cutting mechanism (28) to cut theselected yarn to form a tuft (7) of predetermined length.
 9. A carpetweaving loom according to claim 1, in which the or each tuft formingunit (1) remains stationary and the means to receive and hold the yarntufts at yarn tuft holding sites (8,73) is formed by a tuft carrierwhich moves longitudinally past the or each tuft forming unit (1).
 10. Acarpet weaving loom according to claim 1, in which the or each tuftforming unit (1) is arranged to traverse all or part of the width of theloom and provide tufts (7) for the weaving points passed as the tuftforming unit or units (1) move transversely across the loom.
 11. Acarpet weaving loom according to claim 10, in which the means to receiveand hold yarn tufts are formed by a series of yarn tuft carriers (70)arranged around an axis (71) which extends transversely across the loom,the carriers being (70) rotatable about the axis after all of the tuftretention sites (73) in one of the tuft carriers (70) have been filled.12. A carpet weaving loom according to claim 11, in which the transfermeans comprise a gripper assembly (72) arranged to grip all of the tufts(7) held by a tuft carrier (70) and move them simultaneously to theweaving point.
 13. A carpet weaving loom including at least one tuftforming unit (1) for forming sequentially yarn tufts (7) of a number ofdifferent colors, means to receive and hold at yarn tuft holding sites(8, 73) yam tufts (7) supplied sequentially by the tuft forming unit(1), and transfer means (10, 72) to transfer all of the tufts (7) heldby the yarn tuft holding sites (8, 73) simultaneously to theircorresponding weaving points, characterized in that the or each tuftforming unit (1) supplies yarn tufts to at least twenty yarn tuftholding sites (8, 73) between successive operations of the transfermeans (10, 72), and comprises a yarn selector wheel (20) with provisionfor holding a number of different yarns arranged around it, and means(21) to drive the selector wheel (20) into a selected one of a number ofangularly discrete positions to bring a selected yarn to a loadingposition.